TY - JOUR
T1 - Transbilayer Movement of Phosphatidylserine in Nonhuman Erythrocytes
T2 - Evidence That the Aminophospholipid Transporter Is a Ubiquitous Membrane Protein
AU - Connor, Jerome
AU - Schroit, Alan J.
PY - 1989
Y1 - 1989
N2 - A 31-32-kDa integral membrane protein has been previously identified in erythrocytes as the protein most likely to be responsible for the transbilayer movement of phosphatidylserine (PS) [Connor & Schroit (1988) Biochemistry 27, 848-851]. Using similar techniques, we have identified analogous proteins of identical molecular weights in bovine, equine, ovine, porcine, canine, caprine, and rhesus red blood cells. Similar to human red blood cells, all of the mammalian cells were able to specifically transport an exogenously supplied fluorescent PS analogue from their outer-to-inner membrane leaflet. In addition, transport could be reversibly inhibited with the sulfhydryl-specific inhibitor pyridyldithioethylamine (PDA). PDA-sensitive PS transport was also observed in nucleated human and murine cell lines. Analysis of isolated plasma membranes from 125I-PDA-labeled cells revealed marked labeling of a 32 000-Da component. Attempts to inhibit PS transport by treating the cells with proteases, lectins, or antibody suggested that the 32-kDa polypeptide is an integral membrane protein that does not contain sites critical to its function at the cell surface.
AB - A 31-32-kDa integral membrane protein has been previously identified in erythrocytes as the protein most likely to be responsible for the transbilayer movement of phosphatidylserine (PS) [Connor & Schroit (1988) Biochemistry 27, 848-851]. Using similar techniques, we have identified analogous proteins of identical molecular weights in bovine, equine, ovine, porcine, canine, caprine, and rhesus red blood cells. Similar to human red blood cells, all of the mammalian cells were able to specifically transport an exogenously supplied fluorescent PS analogue from their outer-to-inner membrane leaflet. In addition, transport could be reversibly inhibited with the sulfhydryl-specific inhibitor pyridyldithioethylamine (PDA). PDA-sensitive PS transport was also observed in nucleated human and murine cell lines. Analysis of isolated plasma membranes from 125I-PDA-labeled cells revealed marked labeling of a 32 000-Da component. Attempts to inhibit PS transport by treating the cells with proteases, lectins, or antibody suggested that the 32-kDa polypeptide is an integral membrane protein that does not contain sites critical to its function at the cell surface.
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U2 - 10.1021/bi00451a021
DO - 10.1021/bi00451a021
M3 - Article
C2 - 2611256
AN - SCOPUS:0024808923
SN - 0006-2960
VL - 28
SP - 9680
EP - 9685
JO - Biochemistry
JF - Biochemistry
IS - 25
ER -